#!/usr/bin/python
# -*- coding: iso-8859-15 -*-
from PIL import Image
import argparse

#命令行输入参数处理
parser = argparse.ArgumentParser()

parser.add_argument('file')		#输入文件
parser.add_argument('-o', '--output') #输出文件
parser.add_argument('--width', type = int, default = 80) #输出字符画宽
parser.add_argument('--height', type = int, default = 80) #输出字符画高

#获取参数
args = parser.parse_args()

IMG = args.file
WIDTH = args.width
HEIGHT = args.height
OUTPUT = args.output

ascii_char = list("$@B%8&WM#*oahkbdpqwmZO0QLCJUYXzcvunxrjft/\|()1{}[]?-_+~<>i!lI;:,\"^`'. ")

# 将256灰度映射到70个字符上
def get_char(r,g,b,alpha = 256):
	if alpha == 0:
		return ''
	
	length = len(ascii_char)
	gray = int(0.2126 * r + 0.7152 * g + 0.0722 * b)

	unit = (256.0 + 1)/length
	return ascii_char[int(gray/unit)]


if __name__ == '__main__':
	im = Image.open(IMG)
	im = im.resize((WIDTH,HEIGHT), Image.NEAREST)

	txt = ""

	for i in range(HEIGHT):
		for j in range(WIDTH):
			txt += get_char(*im.getpixel((j,i)))
		txt += '\n'
	
	print txt

	#字符串输出到文件
	if OUTPUT:
		with open(OUTPUT, 'w') as f:
			f.write(txt)
	else:
		with open("output.txt",'w') as f:
			f.write(txt)
